In the following description and claims, the term "rotatable distributor" or "rotary distributer" denotes rotatable outlet deflector nozzles and rotors adapted for establishing reactionary force components and which at times are also referred to as "swivels" or "reaction swivels".
Rotary sprinklers generally fall into two categories, generally referred to in the art as "sprayers" and "sprinklers". Sprayers, typically have essentially low flow rate and short irrigation range, that owing to the essentially high speed of revolution of the distributor, causing atomization of the water jet into spray.
The second category of rotary sprinklers, the so-called sprinklers, are suitable for use with essentially high flow rates and provide irrigation range than sprayers. However, such sprinklers require dynamic seals between the moving parts of the sprinkler. The higher the flow rate of a sprinkler, the larger the size of the seals which entails friction increase, resulting in wear of moving parts, etc.
U.S. Pat. No. 3,034,728 is directed to a lawn sprinkler comprising a water supply pipe vertically extending and formed with a water discharge opening at its upper end with a stem extending through the opening and a reaction-operated rotary drive for rotating the stem about a vertical axis. There is fitted a laterally extending head on the stem above the opening in which the undersurface of the head slopes upwardly and outwardly from the stem in order to deflect water issuing from the opening in a lateral direction and where the slope is uneven along the cross-section of the distribution head.
A serious drawback of the invention disclosed in the '728 patent is that it is devoid of any speed restriction means leading to a sprayer type sprinkler in which the water emitted is in the form of fine spray emitted to an essentially short range. Another serious disadvantage of that patent is that the stem rotatable within the sprinkler's housing has no bearing supports both at its top and bottom end, entailing unstable rotation of the distribution head and possible accelerated wear of various components.
It is an object of the present invention to provide anew and improved rotary drive sprinkler devoid of dynamic seals.